#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <vector>

using namespace std;

int dx[4] = { 1 , -1 , 0 , 0 };
int dy[4] = { 0 , 0 , 1 , -1 };

int ret = 0;
int m = 0, n = 0;

void dfs(vector<vector<char>>& grid, int i, int j)
{
    grid[i][j] = '0';

    for (int k = 0; k < 4; ++k)
    {
        int x = i + dx[k];
        int y = j + dy[k];

        if (x >= 0 && x < m && y >= 0 && y < n && grid[x][y] == '1')
            dfs(grid, x, y);
    }
}

int numIslands(vector<vector<char>>& grid) {
    m = grid.size();
    n = grid[0].size();

    for (int i = 0; i < m; ++i)
    {
        for (int j = 0; j < n; ++j)
        {
            if (grid[i][j] == '1')
            {
                dfs(grid, i, j);
                ret++;
            }
        }
    }

    return ret;
}

int main()
{

	return 0;
}